The court suspended a March 2025 ordinance that had delayed LEZ restrictions by two years, with a final ruling on the potential annulment expected within three months.

The regional legislation delaying the LEZ standards has been halted, and a decision on whether to permanently annul the postponement will be made within three months.

Opposition to the LEZ measures was linked to political campaigns, especially during last year's municipal elections, involving parties like MR, PS, and Engagés, citing health risks.

The delay was challenged by various associations and citizens, citing health risks, especially for children with asthma and allergies, and was supported by a parliamentary majority.

The Brussels Constitutional Court has temporarily suspended the postponement of stricter Low Emission Zone (LEZ) rules, citing the potential harm to children's health, particularly a child with chronic asthma and allergies.

Following the court's decision, outgoing Minister Alain Maron announced that the LEZ taskforce will meet promptly to follow up on the ruling, with further details to be provided after the meeting.

The debate over tightening LEZ standards has been ongoing, with opposition mainly from Francophone liberals, centrists, and some Flemish parties, who initially voted to delay the implementation by two years last year.

The court's decision is a temporary measure pending a final ruling on whether the original LEZ schedule will be enforced, with a final decision expected within three months.

The affected vehicles include diesel Euro 5 cars registered between January 2011 and September 2015, and gasoline Euro 2 cars registered before 2001, although older vehicles are already excluded from Brussels.

The court judged that delaying the LEZ could cause irreparable harm to health and the environment, violating constitutional rights, and thus suspended the ordinance, with a final ruling on annulment to follow.

Environmental and health advocacy groups welcomed the court's decision, viewing it as a relief, and the court acknowledged the health risks posed by postponing the LEZ measures.

This legal ruling highlights ongoing debates about environmental policies and public health priorities in Brussels, with stakeholders seeking a balanced approach to air quality.

Green party members, including outgoing Brussels environment minister Elke Van den Brandt and health minister Alain Maron, praised the decision as a victory for public health and children's safety.